Despite the substantial morbidity and mortality associated with bipolar disorder in adolescence, there are no empirically validated psychosocial interventions for this population to date. The purpose of this Mentored Patient-Oriented Research Career Development Award is to enable the candidate to develop a program of research that integrates clinical, developmental, and neurobiological approaches to the assessment and treatment of affective dysregulation for adolescents with bipolar disorder. The proposed research plan focuses on treatment development and preliminary investigation of a family-based psychosocial intervention targeting affective dysregulation for adolescents with bipolar disorder. The intervention will include age- and illness-related modifications to Dialectical Behavior Therapy (DBT), an evidence-based treatment for adults focused on enhancing emotion regulation skills. Feasibility and efficacy of Family-Based DBT will be examined in the proposed open pilot trial. The study will be conducted at the Child and Adolescent Bipolar Services clinic at Western Psychiatric Institute and Clinic. Sixty adolescents (age 12-18) with bipolar disorder will receive Family-Based DBT. It is hypothesized that DBT will be feasible to deliver and acceptable to this population, and will be associated with improvements in affect regulation, mood symptomatology, and psychosocial functioning over one-year follow-up. Exploratory analyses will examine predictors of treatment response. Training will be sought in: 1) adolescent development, 2) the neurobiology of affect regulation, 3) pharmacological management of pediatric bipolar disorder, and 4) statistical methods for analyzing longitudinal treatment-outcome data. Such training activities will support the research plan by enhancing the candidate's ability to develop, deliver, and assess outcomes for the intervention that incorporate a multidisciplinary approach to emotion regulation. Together, the training and research plans support the candidate's long-term goal of establishing a multidisciplinary program of innovative treatment research targeting affective dysregulation among adolescents with bipolar disorder. Further research in this area is of significant public health importance, as it has the potential to decrease poor outcomes associated with early-onset bipolar disorder, including a deteriorative course into adulthood, chronic psychosocial impairment, treatment resistance, and suicidality.